* {
    box-sizing: border-box;
}

html, body {
    margin: 0px;
    padding: 0px;
}

.main {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    width: 100%;
    height: 100vh;
}

.header {
    width: 100%;
    padding-top: 10px;
}

.footer {
    width: 100%;
    padding-bottom: 20px;
    border-top: 1px solid black;
}